How are rocks different from minerals? Definition of Mineral: 1. Naturally occurring 2. Solid substance 3. Orderly crystalline structure 4. Definite chemical.
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How are rocks different How are rocks different from minerals?from minerals?
Definition of Mineral:Definition of Mineral:
1. Naturally occurring
2. Solid substance
3. Orderly crystalline structure
4. Definite chemical composition
5. Inorganic
Rocks Tell Stories Records of Geologic Past
1. Igneous rocks … from cooling and solidification of lava or magma
2. Sedimentary rocks … from compacted and cemented sediments, or chemical precipitates or evaporites
3. Metamorphic rocks … meta (change) morphic (form) … rocks changed by heat and pressure –but remain solid
Rock Classification – 3 major groups based on their methods of
formation or origin
ESRT – Page 6
IgneousIgneous- rocks that form when molten - rocks that form when molten magma solidifies.magma solidifies.
Lava-magma that reaches the Earth’s surface.
Magma-liquid rock deep within the Earth.
• Intrusive- igneous rocks which form when magma solidifies deep underground.(plutonic)
• Extrusive- igneous rocks which form when lava cools rapidly at Earth’s surface. (volcanic)
FelsicFelsic-lava that is rich in silica, light -lava that is rich in silica, light in color and low density.in color and low density.
MaficMafic-lava that is rich in iron & -lava that is rich in iron & magnesium, dark in color, & high magnesium, dark in color, & high densitydensity
FELSIC
MAFIC
TextureTexture-the size of the mineral -the size of the mineral grains or crystals. (glassy, grains or crystals. (glassy, fine, course)fine, course)
PorphyryPorphyry- a rock that contains a - a rock that contains a mixture of various sized mixture of various sized crystals.crystals.
Igneous Rocks
IGNEOUS ROCKS
Types of Igneous Rock
Type of Texture
Where & How they cool
IGNEOUS ROCKS
Intrusive Extrusive
coarse Very coarse
Vesicular/Non
FineGlassy
Magma cools slowly inside
the earth
Lava cools rapidly at the
Earth’s surface
Non-Vesicular
Type of Igneous Rock
Where & how they cool
Type of Texture
Sedimentary Rock Sedimentary Rock VocabularyVocabulary•ClasticClastic – rocks made up of fragments of other rocks. – rocks made up of fragments of other rocks.
•BioclasticBioclastic- rock formed from the remains of living - rock formed from the remains of living organisms.organisms.
•LithificationLithification- the process of forming a rock.- the process of forming a rock.•Cementation-Cementation- the process of sediments being the process of sediments being
stuck together by minerals in running water.stuck together by minerals in running water.•Compaction-Compaction-process in which air and water are process in which air and water are squeezed out of sediments, forming a sed. rock.squeezed out of sediments, forming a sed. rock.•Precipitation (from solution)- Precipitation (from solution)- when water evaporates when water evaporates and leaves behind the minerals that were dissolved and leaves behind the minerals that were dissolved in the water. in the water.
Sedimentary Rocks
Hints/Clues to look for
TYPES OF
How they formed (method of lithification)
Grain Sizes
Sedimentary
ClasticBioclastic(Organic)
Crystalline(Chemical)
Minerals are dissolved intowater, then the water
evaporates and leaves the minerals behind
Fragments of rocks and organic material
compacted & cementedtogether
Fragmentsof rocks compacted
and cemented together
Pebbles, cobbles,Boulders (mixed)
sand
silt
clay
fossils ofplants or animals Large crystal
Hints/Clues to look for
How Formed (method of Lithification)
Grain Sizes
Metamorphic Rock Metamorphic Rock VocabularyVocabulary
• Recrystallization- the repeated process of melting and solidifying magma into crystals.
• Foliation- a metamorphic rock with visible parallel bands of minerals.
• Regional metamorphism- metamorphism that affects rocks over large areas at tectonic plate boundaries. (heat & pressure)
• Contact metamorphism-metamorphism of a rock due to the extreme heat of contact with magma.
METAMORPHIC ROCKS
Grain Size
Type of Metamorphism
Type of Texture
METAMORPHIC ROCKS
Regional Metamorphism
Contact Metamorphism
Foliated Nonfoliated
CoarseFine MEDIUM Medium CoarseFine
Occurs over a very large area (thousands of Km’s) during tectonic activity. The
movement of tectonic plates creates tremendous heat and pressure at plate boundaries causing the rocks to change
Hot magma pushes through existing rock. The heat from the magma can change the structure
and composition of the existing rock.
Type of Metamorphism
Type of Texture
Grain Size
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